display in their periodical movements that wonderful regularity which
is peculiar to a region where the same wind brings almost always
strata of air of the same temperature; and where the change of the sun
in its declination causes every year at the same period a rupture of
equilibrium in the electric intensity, in the cessation of the
breezes, and the commencement of the season of rains. The Orinoco, the
Rio Magdalena, and the Congo or Zaire are the only great rivers of the
equinoctial region of the globe, which, rising near the equator, have
their mouths in a much higher latitude, though still within the
tropics. The Nile and the Rio de la Plata direct their course, in the
two opposite hemispheres, from the torrid zone towards the temperate.*
(* In Asia, the Ganges, the Burrampooter, and the majestic rivers of
Indo-China direct their course towards the equator. The former flow
from the temperate to the torrid zone. This circumstance of courses
pursuing opposite directions (towards the equator, and towards the
temperate climates) has an influence on the period and the height of
the risings, on the nature and variety of the productions on the banks
of the rivers, on the less or greater activity of trade; and, I may
add, from what we know of the nations of Egypt, Merce, and India, on
the progress of civilization along the valleys of the rivers.)

As long as, confounding the Rio Paragua of Esmeralda with the Rio
Guaviare, the sources of the Orinoco were sought towards the
south-west, on the eastern back of the Andes, the risings of this
river were attributed to a periodical melting of the snows. This
reasoning was as far from the truth as that in which the Nile was
formerly supposed to be swelled by the waters of the snows of
Abyssinia. The Cordilleras of New Grenada, near which the western
tributary streams of the Orinoco, the Guaviare, the Meta, and the
Apure take their rise, enter no more into the limit of perpetual